Collected Evidence: Collected Evidence: Retain dead wood in forest managementWe have found no evidence on the impact of retaining dead wood in forests or woodlands on wild bee communities or populations.  'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F36https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F36Thu, 20 May 2010 12:43:18 +0100Collected Evidence: Collected Evidence: Retain connectivity between habitat patches One before-and-after study in Australia found that retaining native vegetation corridors maintained populations of eight of 13 frog species over 20 years.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F853https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F853Fri, 06 Sep 2013 11:45:40 +0100Collected Evidence: Collected Evidence: Retain crop residuesBiodiversity: One replicated study from Mexico found higher microbial biomass when crop residues were retained. Erosion: One review found reduced water runoff, increased water storage and reduced soil erosion. One replicated site comparison from Canada found mixed effects on soil physical properties, including penetration resistance and the size of soil aggregates. One replicated study from the USA found that tillage can have mixed results on soil erosion when crop remains are removed. Soil organic matter: Two randomized, replicated trials from Australia and China found higher soil organic carbon and nitrogen when residues were retained. One trial found this only when fertilizer was also applied. Yield: Two randomized, replicated trials from Australia and China found higher yields when residues were retained. One trial found this only when residue retention was done combination with fertilizer application and no-tillage. Soil types covered: clay, loam, sandy-loam, silt loam.      Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F907https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F907Wed, 02 Oct 2013 11:38:30 +0100Collected Evidence: Collected Evidence: Retain existing bat roosts and access points within developments Three studies evaluated the effects of retaining existing bat roosts and access points within developments on bat populations. Two studies were in the UK and one was in Ireland. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (3 STUDIES) Use (3 studies): One before-and-after study in Ireland found similar numbers of brown long-eared bats roosting within an attic after existing access points were retained during renovations. One replicated, before-and-after study in the UK found that four of nine bat roosts retained within developments were used as maternity colonies, in two cases by similar or greater numbers of bats after development had taken place. One review in the UK found that bats used two-thirds of retained and modified bat roosts after development, and retained roosts were more likely to be used than newly created roosts. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F947https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F947Tue, 10 Dec 2013 14:08:36 +0000Collected Evidence: Collected Evidence: Retain or plant native trees and shrubs amongst crops (agroforestry) Eight studies evaluated the effects of retaining or planting native trees and shrubs amongst crops on bat populations. Four studies were in Mexico, three were in South America and one was in Tanzania. COMMUNITY RESPONSE (7 STUDIES) Community composition (1 study): One replicated, site comparison study in Tanzania found different compositions of bat species in coffee plantations with different amounts and types of shade cover. Richness/diversity (7 studies): Four of six replicated, site comparison studies in Columbia, Mexico and Costa Rica found a similar number of bat species in shaded and unshaded coffee plantations, and in coffee plantations with different amounts and types of shade cover. The two other studies found more bat species and higher bat diversity in coffee, cacao and banana plantations with varied shade cover, than in plantations with a single shade species or no shade. One replicated, site comparison study in Tanzania found more bat species in shaded coffee plantations than in traditional mixed agroforestry systems with natural forest vegetation. POPULATION RESPONSE (6 STUDIES) Abundance (5 studies): Two replicated, site comparison studies in Mexico captured more bats in coffee plantations with varied shade cover than in plantations with a single shade species. One replicated, site comparison study in Mexico found higher activity (relative abundance) of forest bat species in plantations with a varied shade cover than in plantations with a single shade species, but the opposite was true for open habitat bat species. One replicated, site comparison study in Costa Rica found no difference in the number of bats captured between cacao and banana shade plantations and unshaded monocultures. One replicated, site comparison study in Tanzania found greater bat occurrence in shaded coffee plantations than in traditional mixed agroforestry systems with natural forest vegetation. Condition (1 study): One replicated, site comparison study in Columbia found that great fruit-eating bats captured in ‘silvopastoral’ areas that used agroforestry, along with no chemicals, had higher body weights and body condition scores than those in conventional farming areas. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F963https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F963Fri, 20 Dec 2013 10:35:13 +0000Collected Evidence: Collected Evidence: Retain forested corridors in logged areas Three studies evaluated the effects of retaining forested corridors in logged areas on bat populations. The three studies were in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (1 STUDY) Abundance (1 studies): One replicated, site comparison study in the USA found that bat activity (relative abundance) was significantly higher along the edges of forested corridors than in corridor interiors or in adjacent logged stands, which had similar activity levels. BEHAVIOUR (2 STUDIES)   Use (2 studies): One replicated, site comparison study in the USA found more Seminole bats roosting in forested corridors than logged stands or mature forest. One replicated, site comparison study in the USA found more male but fewer female evening bats roosting in forested corridors than logged stands. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F996https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F996Fri, 20 Dec 2013 15:44:57 +0000Collected Evidence: Collected Evidence: Retain fallen trees We captured no evidence for the effects of retaining fallen trees on forests. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.  Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1193https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1193Thu, 19 May 2016 11:54:12 +0100Collected Evidence: Collected Evidence: Retain nesting trees/shelter for primates within agricultural fields We found no evidence for the effects of retaining nesting trees/shelter for primates within agricultural fields on primate populations. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1430https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1430Tue, 17 Oct 2017 09:53:02 +0100Collected Evidence: Collected Evidence: Retain or create buffer zones between pollution sources and peatlands We found no studies that evaluated the effects, on peatland vegetation, of retaining or creating buffer zones between pollution sources and peatlands. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1781https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1781Tue, 28 Nov 2017 08:14:53 +0000Collected Evidence: Collected Evidence: Retain existing in-field trees We found no studies that evaluated the effects of retaining existing in-field trees on bat populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1945https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1945Tue, 04 Dec 2018 10:03:08 +0000Collected Evidence: Collected Evidence: Retain remnant forest or woodland on agricultural land We found no studies that evaluated the effects of retaining remnant forest or woodland on agricultural land on bat populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this intervention during our systematic journal and report searches. Therefore we have no evidence to indicate whether or not the intervention has any desirable or harmful effects.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1947https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1947Tue, 04 Dec 2018 10:55:06 +0000Collected Evidence: Collected Evidence: Retain buffers around roost trees in logged areas We found no studies that evaluated the effects of retaining buffers around roost trees in logged areas on bat populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1983https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F1983Tue, 04 Dec 2018 19:25:39 +0000Collected Evidence: Collected Evidence: Retain existing bat commuting routes We found no studies that evaluated the effects of retaining existing bat commuting routes on bat populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2029https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2029Wed, 05 Dec 2018 18:20:44 +0000Collected Evidence: Collected Evidence: Retain connectivity between habitat patches We found no studies that evaluated the effects of retaining connectivity between habitat patches on bat populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2031https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2031Wed, 05 Dec 2018 18:22:27 +0000Collected Evidence: Collected Evidence: Retain native forest and woodland We found no studies that evaluated the effects of retaining native forest and woodland on bat populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2033https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2033Wed, 05 Dec 2018 18:24:08 +0000Collected Evidence: Collected Evidence: Retain dead trees after uprooting One study evaluated the effects on mammals of retaining dead trees after uprooting. This study was in the USA. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY) Use (1 study): A replicated, controlled study in the USA found that areas where trees were uprooted but left on site were used more by desert cottontails than were cleared areas. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2642https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2642Fri, 12 Jun 2020 15:55:19 +0100Collected Evidence: Collected Evidence: Retain buoys and lines at the sea floor or river bed when not hauling We found no studies that evaluated the effects of retaining buoys and lines at the sea floor or river bed when not hauling on marine and freshwater mammal populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2798https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2798Thu, 04 Feb 2021 16:40:23 +0000Collected Evidence: Collected Evidence: Retain offal on fishing vessels instead of discarding overboard We found no studies that evaluated the effects of retaining offal on fishing vessels instead of discarding overboard on marine and freshwater mammal populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2827https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2827Fri, 05 Feb 2021 15:58:14 +0000Collected Evidence: Collected Evidence: Retain or create buffer zones around important habitats We found no studies that evaluated the effects of retaining or creating buffer zones around important habitats on marine and freshwater mammal populations. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2919https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F2919Mon, 08 Feb 2021 16:34:46 +0000Collected Evidence: Collected Evidence: Retain or increase leaf litter or other types of mulch Two studies evaluated the effects of retaining or increasing leaf litter or other types of mulch on reptile populations. One study was in Indonesia and one was in Australia. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One replicated, randomized, controlled, before-and-after study in Indonesia found that reptile species richness increased with the addition of leaf litter and decreased following removal of leaf litter and woody debris. POPULATION RESPONSE (2 STUDIES) Abundance (2 studies): Two randomized, controlled studies (one replicated, before-and-after study) in Indonesia and Australia found that the addition of leaf litter or cacao husks resulted in a higher abundance of overall reptiles or skinks. One study also found that removal of leaf litter and woody debris led to a decrease in reptile abundance. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3525https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3525Tue, 07 Dec 2021 15:12:59 +0000Collected Evidence: Collected Evidence: Retain buoys and lines at the sea floor or riverbed when not hauling We found no studies that evaluated the effects on reptile populations of retaining buoys and lines at the sea floor or riverbed when not hauling. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3555https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3555Wed, 08 Dec 2021 14:08:50 +0000Collected Evidence: Collected Evidence: Retain offal on fishing vessels instead of discarding overboard We found no studies that evaluated the effects on reptile populations of retaining offal on fishing vessels instead of discarding overboard. ‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3556https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3556Wed, 08 Dec 2021 14:10:15 +0000Collected Evidence: Collected Evidence: Retain connectivity between habitat patches Two studies evaluated the effects of retaining connectivity between habitat patches on reptile populations. One study was in Brazil and one was in Madagascar. COMMUNITY RESPONSE (2 STUDIES) Community composition (2 studies): One replicated, site comparison study in Brazil found that forest fragments connected by corridors and isolated forest fragments had similar reptile species composition. One site comparison study in Madagascar found that in an area with hedges connecting different habitat types, reptile communities were more similar across the different habitat types than in an area with no hedges. Richness/diversity (2 studies): One replicated, site comparison study in Brazil found that forest fragments connected by corridors and isolated forest fragments had similar reptile species richness. One site comparison study in Madagascar found that an area with hedges connecting different habitat types had more unique reptile species than an area without hedges. POPULATION RESPONSE (1 STUDY) Abundance (1 study): One replicated, site comparison study in Brazil found that forest fragments connected by corridors and isolated forest fragments had a similar abundance of reptiles, including leaf litter lizards. BEHAVIOUR (0 STUDIES)Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3663https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3663Fri, 10 Dec 2021 10:57:48 +0000Collected Evidence: Collected Evidence: Retain connectivity between habitat patches Three studies evaluated the effects on butterflies and moths of retaining connectivity between habitat patches. One study was in each of the USA, the Netherlands and Estonia. COMMUNITY RESPONSE (1 STUDY) Richness/diversity (1 study): One replicated, paired, site comparison study in Estonia found that well connected cleared patches within a woodland had a similar species richness of butterflies to isolated cleared patches. POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (2 STUDIES) Use (1 study): One replicated, site comparison study in the Netherlands found that low quality habitat patches which were well connected were more likely to retain Alcon large blue populations than less well connected patches, but connectivity did not affect occupancy of high quality patches. Behaviour change (1 study): One replicated, controlled study in the USA found that common buckeye were more likely to colonize farther away habitat patches if they were released on corridors of suitable habitat than if released in unsuitable habitat, but there was no difference when released close to habitat patches. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3832https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3832Mon, 04 Jul 2022 14:39:38 +0100Collected Evidence: Collected Evidence: Retain or plant trees to act as windbreaks One study evaluated the effects on butterflies and moths of retaining or planting trees to act as windbreaks. This study was in Sweden. COMMUNITY RESPONSE (0 STUDIES) POPULATION RESPONSE (0 STUDIES) BEHAVIOUR (1 STUDY) Use (1 study): One site comparison study in Sweden reported that sheltered grassland strips were more likely to be used by one of four butterfly species than strips providing nectar resources or no resources. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3861https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F3861Tue, 05 Jul 2022 15:39:41 +0100
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

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